Observer is satyam

Atma the observer is Satyam. Means does not undergo any change, and is available all 3 periods of time , is consciousness.

Time, space etc. are always objects of consciousness. And consciousness is always the subject.

The objects of consciousness are mithya. Mithya is there reality.

Means, has no independent existence.

When we say any object exists, its existence actually is the existence belonging to its cause, which is consciousness. So consciousness is actually the cause as well. And also happens to be the object.

Mahavakya vichara

Self is understood as poornam brahman, by understanding the mahavakya.

mahavakya has 3 parts. tat pada, tvam pada and asi pada.

By understanding the pada artha vakyartha can usually be understood. In certain vakyas lakshyartha has to be taken for understanding. It is commonly used, such as when saying this is that lakshman you see, meaning there are not 2 lakshman, but same person.

Also we say brown has won. etc. to refer to brown horse.

So here tat pada refers to entire prapancha, subject and object and maya shaktivaan consciousness.

Tvam pada refers to individual body mind subject consciousness.

both are one and the same , only if we understand the formful meanings as mithya understanding and formless truth as satyam.

The truth of atma is formless consciousness, can be understood first via drk drshya viveka, and then totally understood via mahavakya as the formless reality which is non dual, which is both purna ishvara and purna as jiva in the scheme of things that is purna. 

Doubts about brahma jnanam

Q: How can matter be consciousness?
consciousness is never an object
consciousness how can it be material given opposite nature

A: We do not say that consciousness is matter. Rather we say that matter is consciousness.
It becomes difficult to understand only when we don't assimilate that matter is not satyam rather is mithya. If matter is mithya , means there is no such thing as matter.

Air, water etc the elements, the elementals, the various objects that we encounter and see as moving and non moving, they do not exist non separate from their cause.

We just need to understand that part.

That matter has it cause as consciousness. Then we can accept matter, as non separate from consciousness.  As not other than consciousness. As not a second entity. Any material entity is not other than the non dual consciousness entity,

The materiality includes name form and various attributes, but the consciousness aspect of the cause is inhibited. We cannot ask where in the effect is the cause, we cannot ask if the cause if embedded or inside the effect, the effect IS the cause. But the attributes differ totally.